1. Field of the Invention
The present invention relates to an improved device enabling to measure the absorption and/or light diffusion of objects, as well as a method for measuring the absorption and/or light diffusion of biological elements.
2. Discussion of the Background
To measure the light absorption of biological elements, a well-known method is the photo-thermal deflection measurement. This method is presented in the document [1] listed at the end of the present description.
It consists of irradiating an object the absorption of which is to be measured using a “pump” beam. Part of the energy of the “pump” beam is then absorbed by the object and leads to a graded index in the surrounding environment(s). Another light beam, known as a “pumping” beam crossing this graded index then undergoes a deviation. Measuring the deviation of a “probe” beam can enable to quantify the graded index. This measurement then makes it possible to deduce the light absorption of the object.
This method is, however, limited. It may not be sufficiently precise for some applications that require a high degree of sensitivity of detection such as for example the measurement of the hybridization of DNA strands.
Another method, known as “resonance by surface plasmon”, can be used to measure the light absorption of biological samples. This method is presented in document [2]listed at the end of the present description.
This “resonance by surface plasmon” method has the particular drawback of requiring adjustments which have to be renewed for each biological sample measured.
For some applications requiring the measurement of a large number of samples, as for example the measurement of DNA strands hybridization on a biochip, this method can turn out to be very long to implement.
The problem consists in being able to carry out detailed measurements of samples of biological elements more quickly than the methods under the previous technology.